Apparatus for obtaining fibers from the stalks of flax and other bast plants



Aug. 1, 1939. E DODD 2,168.095

APPARATUS FOR OBTAINING FIBERS FROM THE STALKS or: FLAX AND OTHER BASTPLANTS Filed May 23, 1938 I 17/. David Patented Aug. 1, 1939 UNITEDSTATES APPARATUS FOR OBTAINING FIBERS FROM THE STALKS OF FLAX AND OTHERBAST PLANTS Albert Ernest Dodd, Woodford, Dromara, Northern IrelandApplication May 23, 1938, Serial No. 209,582 In Great Britain September27, 1937 1 Claim.

This invention relates to apparatus for decorticating the stalks of flaxand other bast plants for the purpose of removing woody or pulpy matterand obtaining fibers therefrom, the invention having particularreference to apparatus for this purpose of the kind embodying a seriesof pairs of fluted rollers through which the flax or the like is passed,the rollers of each pair being pressed into contact with one another byspring or other suitable means.

The object of the present invention is to devise an improved form ofmachine of the above character which will enable a larger output ofbetter quality fiber to be obtained from a machine of given capacity ascompared with apparatus of this kind as hitherto proposed or adopted.

The invention consists in apparatus of the kind referred to in which thecoarseness of the flutes varies progressively through the machine sothat the coarsest flutes are at the feed end and the finest flutes atthe exit end, each succeeding pair of rollers throughout the machinerevolving at a slightly higher surface speed than the preceding pair andthe spring or like pressure urging the rollers into contact but notbottoming contact varying with the flute pitches so that the pressure isgreatest for the coarsest pitches and lowest for the finest pitches.

Further features of the invention will be apparent from the descriptiongiven hereafter.

The accompanying drawing illustrates one mode of carrying out theinvention.

Figure 1 is a side elevation (with parts omitted) of one form ofapparatus in accordance with the invention, and

Figure 2 is a plan.

In carrying my invention into effect in one convenient manner I form myimproved apparatus with any suitable foundation, framework 40 orbed-plate a, and upon this I arrange a series of pairs of rollers b cwhich are fluted or similarly formed upon their surface, and which areso arranged that when pressed into contact the flutes of one roller areprevented from bottoming 45 the grooves of the companion roller byapproximately of an inch, for the coarsest pitched rollers and aproportionally lesser amount for the finer pitches. One roller of eachpair, say the lower roller 0, is mounted in fixed bearings 50 and isarranged to be power driven by suitable gearing 11 while the companionroller b of each pair is mounted in sliding bearings and spring pressedinto contact with the lower roller, the spring pressed roller beingeither positively driven 55 or driven by frictional contact with thefixed bearing roller as may be desired. The rollers of succeeding pairsare varied in diameter, so as to vary the peripheral speeds and theyalso vary in the pitch of the flutes, and the spring pressure is soadjusted that it is greatest for the 6 largest rollers and those havingthe coarsest pitch of flutes, and is lowest for the smallest rollers andthose having the finest pitch. For example, I have found verysatisfactory results by the use of spring pressures varying from 250 10lbs. for rollers having a number of flutes equal to four times thediameter, in inches, to 100 lbs. for rollers having a number of flutesequal to twelve times the diameter of the roller, in inches.

In the specific embodiment of the invention 15 illustrated in thedrawing I provide the machine with 34 pairs of intermeshing flutedrollers, and arranged in four sections A, B, C and D. The first sectionA, for example, would contain three pairs of rollers varying indiameters fro-m 4+2" 20 to 5", and having 18 flutes, and 3 pairs withthe same varying diameters and 28 flutes. The second section B consistsof seven pairs of rollers varying progressively in diameter from 4% out-7 side diameter to 4 /2" and having 8 flutes per 25 inch diametralpitch. The third section C would consist of 9 pairs of rollers varyingprogressively in diameter from 3.5" diameter to 3.7 and each rollerwould have 10 flutes per inch diametral pitch. The fourth section Dwould have 12 pairs 30 of rollers varying progressively in diameter from2%" to 2 7 and each roller would have 12 flutes per inch diametralpitch. In the first section the depth of space between a flute of oneroller and the corresponding groove of the com- 35 panion roller wouldbe .065" for the first three pairs and .0514" for the second threepairs. The corresponding dimensions for the second, third and fourthsections would be. .050", .046" and .0227" respectively. The springpressures employed would vary from 250 lbs. for the rollers with 4flutes per inch diametral pitch, to 100 lbs. for the rollers with 12flutes per inch diametral pitch. Each of the four sections would bedriven from one main driving shaft by separate gearing so arranged thatthe percentage increase of surface speed between the last roller pair ofone section and the first roller pair of the succeeding section is thesame as between the succeeding roller pairs in each section. For thispurpose a suitable change wheel would be incorporated in the drivinggears for each several section.

I have found that with a machine constructed in accordance with theforegoing description I am able to reduce the bulk of the flax by 70 perfilled.

I claim: Apparatus for decorticating the stalks of flax and other bestplants of the kind embodying 2.

series of pairs of fluted rollers through which the flax or the like ispassed, means for pressing the rollers of each pair into contact withone another, the pitch of the flutes of each pair of rollersprogressively decreasing through the machine, the pressure of thepressing means varying with the flute pitches of each pair of rollers sothat the pressure is greatest for the coarsest pitches and lowest forthe finest pitches, and

means for revolvin'g each succeeding pair of 10 rollers throughout themachine at a slightly higher surface speed than the preceding pair.

ALBERT ERNEST DODD.

